Lime soap dispersant



United States Patent 3,528,923 LIME SOAP DISPERSANT James G. Atherton, Hoffman Estates, Harold C. Nemeth,

Chicago, and Eugene J. Miller, Jr., Wheaten, 10., assignors, by mesne assignments, to Armour Industrial Chemical Company, a corporation of Delaware No Drawing. Filed Oct. 5, 1967, Ser. No. 673,010 Int. Cl. Clld 1/22, 1/28, 9/32 US. Cl. 252121 4 Claims ABSTRACT OF THE DISCLOSURE Sulfonated phenylstearic acids as lime soap dispersants in soap compositions. Processes for preparing such compositions and processes for using such dispersants with soap in water.

Lime soap is the water-insoluble scum or curd frequently formed in the wash water when soap is used for laundering, personal washing, and bathing, especially in the presence of hard Water. It is particularly objectionable because of its ability to stick to surfaces such as bathtubs, washing tubs, clothes and the like surfaces with which it comes into contact; and because of its ability to resist removal therefrom.

The generally accepted method for reducing and minimizing the objectionable effects of lime soap is through the use of lime soap dispersants. The most widely used lime soap dispersants are synthetic surface active agents, generally in the form of their alkali metal salts, although only a very few of such agents have the necessary qualifications to be useful as lime soap dispersants. As can be appreciated, therefore, a constant demand for better and more economical lime soap dispersants exists.

We are aware that prior workers in the art have suggested the combination of various sulfonated compounds with soap to impart soap dispersion characteristics (U.S. Pats. 2,944,028; 3,043,779 and 3,055,837). None of these patents, however, suggests the use of a sulfonated arylalkyl acid, and particularly wherein the acid function is not neutralized with an alkali metal.

Therefore, it is an object of this invention to provide a novel lime soap dispersant for soap formulations. Another object of this invention is to provide a soap composition having incorporaetd therein a novel lime soap dispersant. Other objects and advantages will become apparent from the ensuing description and examples.

As more fully hereinafter described, we have discovered that un-neutralized sulfonated phenylstearic acids are effective lime soap dispersants in aqueous media containing soap, said sulfonated phenylstearic acids being of the general formula:

(SOsH)b wherein x and y each are integers ranging from 0 to 14 and whose sum is 14; and a and h each are integers ranging from 0 to 1 and whose sum is an integer ranging from 1 to 2. The sulfonation takes place at the alpha carbon atom to the carboxyl function and at the aromatic ring, depending upon reaction conditions. Referring to the hereinabove formula, a will be 1 and b will be 0 when the sulfonation is carried out in carbon tetrachloride using dioxane-sulfur trioxide complex at about 60 C. When an 8:1 molar ratio of 95% sulfuric acid to aryl 3,528,923 Patented Sept. 15, 1970 "ice EXAMPLE I sulfonation of phenylstearic acid To a one liter, four neck creased flask equipped with a mechanical stirrer, thermometer, reflux condenser having a drying tube and a dropping funnel, is added 25.0 ml. of chloroform and 21.0 grams (0.263 mole) of S0 at a temperature of 1015 C. Ninety grams (0.25 mole) of phenylstearic acid is slowly added, with cooling and stirring, over a one hour period at a temperature of 4-5 C. Stirring is continued for an additional 1% hours at 10-30 C., and the mixture is allowed to stand at room temperature overnight. The reaction mixture is then refluxed at a temperature of 60-64 'C. for about one hour and the chloroform is removed under reduced pressure. 111.1 grams (calculated 110.0 grams) of a black, viscous oil is obtained.

Analysis:

Neutralization equivalent 244 Calculated neutralization equivalent 220 Activity, percent 90.2

Under infrared analysis the resulting product appears as a mixture of alpha-sulfonation and arylsulfonation with a majority or preponderate of the product being alphasulfonated.

As used herein, the term soap refers to the watersoluble metallic, ammonium, or organic base salts of a fatty acid or mixtures of fatty acids which are capable of being used as washing and cleansing agents. Any of the water-soluble soaps formulated for industrial, household or toilet use may be employed. Further, the character of the soap constituent may vary widely in its composition depending on whether the final soap composition is to be in powder, spray-dried, flake, bar, paste, liquid or other form. Water-soluble soaps such as the sodium soaps and other suitable alkali metal, ammonium, or amine soaps derived from such fats and oils as tallow, coconut oil, cottonseed oil, soybean oil, corn oil, lard, greases, fish oils and the like, as well as their hydrogenated derivatives, and mixtures thereof, properly blended to yield the desired soap quality, may be used in the soap compositions of the present invention. In general, the watersoluble sodium salts of fatty acids derived from tallow and coconut oils are preferred because of the ease with which they may be formed into a bar.

The amount of the lime soap dispersant to be used with the soap may vary, depending upon the end use, type of soap employed, pH conditions, water hardness and the like. In general, any amount above about 1% by weight based on the weight of soap in the compositions will exhibit satisfactory lime soap dispersant properties. However, it is preferred that amounts of lime soap dispersants, on a weight ratio to soap, of from about 5:95 to 70:30% be utilized. It will be understood that lesser or greater amounts will be effective but without substantial further advantage.

The resulting soap composition of the present invention, that is, the soap and the lime soap dispersant composition, is generally effective when used in aqueous systems inconventional amounts, such as-is normally used with soap compositions, and which is generally above about 0.01% concentration.

The method of incorporating the lime soap dispersants of the present invention into soap, which is preferably 3 molten for uniform distribution, is not critical. Thus they can be added to the crutcher after the soap has been made; or, if desired, they can be added to soap chips in the amalgamator along with other soap additives conventionally used.

The soap compositions in which the lime soap dispersant may be incorporated may also contain, if desired, other ingredients, in amounts usually below about 50% by weight of the soap, which are commonly used with soaps, such as, synthetic detergents of the anionic and nonionic types, polyphosphate builders, anti-redeposition agents such as carboxymethylcellulose, brightening agents such as fluorescent dyes, bleaching agents, pigments, perfumes and the like, as long as the usual considerations of compatibility are applied. With respect to the foregoing mentioned synthetic detergents, the anionic types can be broadly described as those detergents having pronounced cleansing power and including in their molecular structure an alkyl radical containing from 6 to 18 carbon atoms and a sulfonic acid or sulfuric acid ester radical. Organic base, ammonium, sodium, or potassium salts of the anionic type detergents can be used. The main types of detergents falling within this class are the alkylaryl sulfpnates, such as sodium or potassium dodecylbenzene sulfonate, sodium or potassium octylnaphthalene sulfonate; the alkyl sulfates such as sodium or potassium salts of the oleic acid amide of methyltaurine; and the sulfonated mono glycerides, such as the mono-coconut oil fatty acid ester of 1,2-hydroxypropane-3-sodium sulfonate. Of this class, linear alkyl groups are especially desirable because of their biodegradable features; and preferably they contain 12 to 14 carbon atoms in their alkyl group, such as dodecylbenzene sulfonate or tridecylbenzene sulfonate. The nonionic type synthetic detergents which are useful in this invention can be broadly described as those detergents which do not ionize in solution, but owe their water-solubility to nonionizing polar groups such as hydroxyl or ether linkages. The main types of detergents falling within this category are the polyoxyethylene ethers of the higher fatty alcohols and alkyl phenols; the polyethylene glycols of fatty acids; fatty alkylol amide condensation products; condensation products of ethylene oxide and a fatty acid ester of a polyhydric alcohol or sugar; and the detergents prepared by heating together a higher fatty acid with diethanol amine. Examples of suitable synthetic nonionics include ethylene oxide-fatty alcohol fatty acid reaction products; iso-octyl-phenol-ethylene oxide reaction products; and combinations of isooctylphenolethylene oxide with coconut oil fatty acidethylene oxide reaction products.

Reference is now made to specific examples illustrating some of the benefits that can result from utilizing the preferred sulfonated phenylstearic acids as lime soap dispersants.

EXAMPLE II The lime soap dispersing properties of the hereinabove described mixture of alpha and aryl sulfonated phenylstearic acids were evaluated by measuring the height of lime soap curd on aging as follows:

90 cc. of a standard hard water (of 334 p.p.m. as expressed for calcium carbonate), is added to a 100 cc. graduated cylinder, and cc. of a 1% soap solution and suificient demineralized Water to make a total amount of 100 cc. are added. The cylinder is shaken for 15 seconds and the foam volume (in cubic centimeters) is determined. The cylinder is allowed to set for 5 minutes and the foam volume and curd volume are again measured. Effective lime soap dispersants decrease or minimize the height of lime soap curd. The smaller the foam and curd volumes after setting, the more effective is the particular soap composition for inhibiting lime soap formation. The results of this evaluation are set forth in Table I. In Table I, each sample number represents the average of 7 runs.

TABLE I.SULFONATED PHENYLSTEARIC ACID Sample number Ingredients 1 2 3 4 5 6 7 1% tallow soap 5. 0 5. 0 5. 0 5. 0 5. 0 5. 0 5. O 1% sulfonated phenylstearic acid 5.0 4.0 3.0 2.0 1.0 Demineralized water 5. 0 1. 0 2.0 3.0 0 Hard water (334 p.p.rn.

GaCOa) 90.0 90.0 90.0 90.0 90. 0 90.0 90. 0 1% sodium lauryl sulfate 1. 0 Results:

Initial foam (cc.) 5 minute foam (cc) cc. of curd The data in Table I clearly show the remarkable improvement in lime soap dispersion due to the introduction of sulfonated phenylstearic acids in accordance with the present invention (sample Nos. 2, 3, 4, 5 and 6). Samples 5 and 6 show a comparison with a known sulfate lime soap dispersant which was not nearly as effective as the slufonated phenylstearic acids at the same concentration.

EXAMPLE III TABLE II.SODIUM SALTS OF SULFONATED PHENYL STEARIC ACID Sample number Ingredients 1 2 3 4 5 6 1% tallow soap 5. 00 5. 00 5. 00 5. 00 5. 0O 5. O0 1% sulfonated phenylstearic acid 5. O0 Sodium salt of sulfonated phenylstearic acid 5.00 5.00 5. 00 5.00 Percent neutralization 50 25 10 Deionized water 5. 00 Hard water (334 p.p.m.) 90.00 90.00 90. 00 90.00 90.00 90. 00 Results:

Initial foam (cc.) 3 5 7 10 6 7 5 minute foam (cc.) 3 3 4 8 4 4 Ce. of curd 8. 5 1. 5 15 15 11 11 EXAMPLE 1V Using the method described in Example II, the alpha and aryl sulfonated phenylstearic acid mixtures were evaluated as lime soap dispersants in mixes of coco-tallow soaps.

An additional measure of lime soap dispersion was performed for these samples by filtering the curd off after the sample had settled 5 minutes and then determining the hardness of the remaining solution by titrating with Versene. The result is expressed as a percentage of original hardness, thus a higher value for the titration evaluation indicates better lime soap dispersion.

The results of both the curd height measurement and the titration evaluation are set forth in Table III.

TABLE III.-SULFONATED PHENYLSTEARIO ACID-PC000- TALLOW SOAP Sample number Ingredients 2 3 4 5 1% coco soap r 1. 0 1. 2 1. 5 2. 5

1% tallow soap 4. 0 4. 0 3. 5 2. 5

1% sulfonated pheuylstear 0. 5 0. 3 0. 5 0.3

Demineralized water 5. 0 4. 5 4. 5 4. 5 4. 5

Hard water (334 p.p.m. CEICOs) 90. 0 90. 0 90. 0 90. 0 90. 0 Results:

Initial foam (00.) 4 4 5 6 6 5 minutes foam (cc.) 3 3 4 3 4 of standard) 61 78 78 67 61 While in the foregoing specification this invention has been described with respect to certain soap formulations containing particular lime soap dispersants and the use of such compositions with a degree of specificity for purposes of illustration, it is not so limited; and it is to be understood that variations and modifications thereof, obvious to those skilled in the art, may be made Without departing from the spirit or scope of our invention.

What is claimed is:

1. A soap composition consisting essentially of a watersoluble soap selected from the group consisting of metallic and ammonium salts of fatty acids an an amount at least 1% by weight based on said soap of a lime soap dispersant, said dispersant being a sulfonated arylalkyl acid represented by the formula:

a Db wherein x and y each are integers ranging from 0 to 14 and whose sum is 14, and a and b each are integers ranging from 0 to 1 and whose sum is an integer ranging from 1 to 2.

2. The soap composition of claim 1 in which said amount is from 5 to 70%.

3. The soap composition of claim 1 in which said acid is a mixture of alpha sulfonated phenylstearic acid and a sulfonated phenylstearic acid wherein the phenyl ring is sulfonated.

4. The composition of claim 3 in which said mixture is preponderately alpha sulfonated phenylstearic acid.

References Cited UNITED STATES PATENTS 11/1942 Stirton et a1. 252354 7/1889 Twitchell 260-402 US. Cl. X.R. 252138, 161, 354 

